Method and apparatus for extinguishing fires



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Patented Sept. 15, 1942 Search Room METHOD AND APPARATUS FOR EXTIN GUISHIN G FIRES Harry Ensminger, Evanston, and Charles A. Getz,

Glen Ellyn, Ill., assignors to Cardox Corporation, Chicago, 111., a corporation of Illinois Application July 26, 1940, Serial No. 347,808

15 Claims.

This invention relates to new and useful improvements in methods and apparatus for extinguishing fires in general but deals more specifically with the extinguishment of such troublesome fires as those involving large quantities of highly inflammable fluids, such as oils, gasoline, cooking and heating burner fuels, etc., which are usually confined in tanks, containers, casings, pools, or the like that may be formed of combustible or non-combustible materials.

The extinguishment of fires involving large quantities of highly inflammable fluids, normally intended to be confined in large or bulk quantities, presents an extremely difficult problem. The extinguishing medium most frequently employed for combating ordinary fires, i. e., hydrant water, is of no practical value against inflammable fluids because its principal effect is to spread the fire to surrounding properties. Attempts have been made to combat this type of fire by means of liquid chemicals and chemical-water combinations, some of which operate on the principle of providing a foam or surface binder to effect smothering of the fire. Only a few of these well known forms of chemical extinguishers have survived the experimental stages for this type of use. Their principal deficiencies have been found to be- (11) Their inability to be discharged in suificient quantities to be effective in combating fires involving any substantial amount of inflammable fluid,

(b) Their inability to be discharged at a velocity which is sufiiciently high to reach the seat of the fire when required to travel against or in conflict with the strong convection currents of hot gases rising from the fire and, with exposed outdoor hazards, as a result of strong natural winds which are frequently encountered, and

(c) The difficulty encountered in preventing freezing of the water where it is employed in combination with chemicals which are stored at a location that is exposed to varying climatic conditions.

Certain hazards of this general type involve directly associated equipment of an extremely expensive character, the value of which far exceeds the value of the involved inflammable fluid. Large electrical power transformers and circuit breakers afford an excellent example of this character of hazard. The casings for this type of equipment usually contain upwards of a thousand gallons of what is known as transformer oil. When this oil becomes ignited, as a result of excessive arcing, or the like, the resultant fire is an extremely stubborn one to combat. electrical equipment of each such transformer or circuit breaking unit is valued at several thousand dollars, and, of course, is the part of the unit which must be maintained in an undamaged condition, when a fire occurs, or the extinguishing medium will not be approved. Many of the chemical extinguishing mediums are as destructive of electrical equipment as fire itself and, for that reason, are entirely unsatisfactory. The liquid chemical compounds which produce a surface binder to smother the fire are unsatisfactory because of the expense involved in cleaning the equipment to remove the deposit of chemical residue which remains thereon.

It has been determined by extensive tests that carbon dioxide, if applied in a certain manner or by a certain method, will completely extinguish fires involving large quantities of highly inflammable fluids in a very efficient manner and in a sufficiently short length of time to prevent any involved equipment from becoming damaged by the fire. This type of extinguishing medium, also, may be employed very successfully to prevent spreading of the fire to surrounding properties as a result of the inflammable fluids being liberated from their confining tanks, or the like.

Carbon dioxide will not damage any object with Which it comes in contact and when it is in liquid form, it will not solidify or freeze unless it is suddenly released to the atmosphere or is subjected to a temperature of at least 'I0 F. It will not leave a deposit of residue which must be removed before the equipment can again be placed in service. A deposit of carbon dioxide snow will remain after the discharge has been stopped, but this snow quickly sublimes and passes off as vapor, leaving the surfaces on which it had accumulated entirely undamaged. Therefore, this medium is not chargeable with the principal objections which prohibit the use of other chemical extinguishing mediums.

In practicing the method of extinguishing fires embodying this invention, certain characteristics peculiar to the burning of highly inflammable materials, such as fluids normally confined in storage tanks, or ther containers, are taken into consideration.

For example, so-called highly inflammable fluids will not actually ignite or burn while in liquid form. Their vapors, however, when mixed with the proper amount of oxygen, will form a highly inflammable fuel mixture which will ignite when subjected to an ignition temperature and will continue to burn as long as a combustible The temperature exists. Even though the fire, which is consuming the vapor and oxygen fuel mixture, is completely extinguished by the application of an extinguishing medium, the fuel mixture will reflash or rekindle if sufficient heat can be extracted from any bodies, masses, objects, or the like, located in heat exchange relation thereto to again provide the necessary ignition temperature.

It is obvious from the above facts that extinguishment can only be effected in the first instance and that reflashing or rekindling can only be prevented in the second instance by cooling below the ignition and combustion temperatures all involved bodies, masses, or objects. In the case of a burning body of highly inflammable fluid, normally confined in a tank, or other container, it is necessary to cool the body of fluid from which the vapors for the fuel mixture are obtained, the vapors rising from such body of fluid, the air from which the oxygen is obtained to support combustion, the fuel mixture of vapors and oxygen, and the walls of the confining tank or container. Additionally, all other objects or bodies which are positioned in heat exchange relation to the fuel mixture, etc, must be similarly cooled to prevent reflashing or rekindling.

Liquid carbon dioxide, when released to the atmosphere, is an excellent cooling medium because the mixture of vapor and snow, formed as a result of such release, possesses a temperature of --110 F. Therefore, carbon dioxide may be employed to accomplish the necessary cooling to effect complete extinguishment of the fire and to prevent reflashinz, or rekindling. However, when employed for this purpose, the carbon dioxide must be delivered in such a manner and at such a velocity as to enable it to reach all of the aforesaid bodies, masses, and objects notwithstanding the presence of strong counter air currents. The carbon dioxide, also, must be released at a rate which is sufiiciently high to provide the required quantity of heat absorbing material to effect the desired quick cooling of all of the involved bodies, masses, etc.

Of course, carbon dioxide has been used as a fire extinguishing medium for a considerable length of time. The most frequently practiced method of employing carbon dioxide, however, involves the discharge of the same at a very slow rate and at a low velocity. The equipment employed for this type of release has always consisted of one or more storage cylinders, usually not exceeding a capacity of 50 pounds, for confining the liquid carbon dioxide and a flared horn through which the resultant snow and vapor mixture is discharged. The inherent limitations of this equipment are such that the highest rate of release is approximately 150 pounds per minute per nozzle and the velocity of discharge at a distance of 4 feet from the end of the horn is approximately 3,000 feet per minute, while at feet the velocity drops to about 1,800 feet per minute. Such a rate of release is entirely inadequate to combat a fire which involves other than a very small amount of highly inflammable fluid. The velocity of discharge is so low that the stream of vapor and snow will not penetrate to the seat of a sizeable fire because of the strong updraft of hot gases. guishing medium by this type of equipment, also, will be prevented if a conflicting natural wind of but a few miles an hour is present.

The method and apparatus embodying this invention involves the bulk storage of liquid carbon Proper application of the extindioxide in units ranging from 1, 2, or 3 tons up to as much as tons, if such a large capacity is needed. A maximum rate of discharge of 6 tons per minute has been found to be entirely ade quate for all hazards so far encountered. However, rates of 15 tons per minute, or more, can be provided if such a high rate is found to be necessary. Because of this large bulk storage and high rate of release, it has been possible to obtain velocities of discharge in excess of 12,000 feet per minute at a distance of 10 feet from the point of release to the atmosphere and a velocity in excess of 4.500 feet per minute at a distance of 20 feet. Because of this type of discharge, fires involving several thousand gallons of oil, which have been permitted to burn for several minutes to create temperatures as high as 1,600 F. have been completely extinguished and all involved bodies, etc., cooled below the combustion and ignition temperatures within a discharge period of but one minute. Certain of these extinguish ments were carried out in the presence of horizontal air currents moving at a rate in excess of 30 miles an hour.

A second characteristic of confined, highly inflammable fluid fires, which is taken into consideration in the practicing of this improved fire extinguishing method has to do with the formation of the combustible fuel mixture. It has been determined that the proper fuel mixture is not formed right at the surface of the body of fluid from which the vapors are obtained. The combustible fuel mixture is not formed until the rising vapors have had an opportunity to mix with the proper amount of oxygen. As a result, the actual combustion zone is located a considerable distance above the exposed surface of the body of fluid.

In practicing the method of this invention, the carbon dioxide is discharged in a very particular or special manner with respect to the top of the body of fluid. Its discharge is employed to effect cooling of the body of liquid, cooling and diluting of the vapors, and cooling and diluting of the vapor and oxygen fuel mixture. The cooling must be suflicient to lower the temperature of these elements below the combustion temperature of the fuel. The carbon dioxide, also, is discharged in a proper manner to cut off the movement of vapors from the surface of the body of fluid to the combustion zone. Although completely cutting off this flow of vapors is the most desirable result to be accomplished, extinguishment also may be accomplished if the vapors rising from the surface of the body of fluid are diluted sufliciently to prevent the formation of a combustible fuel mixture when it is combined with oxygen.

When a large tank of inflammable fuel is ignited, the principal combustion zone is located above the top of the fluid surface, or above the top of the tank. The vapors rising to this combustion zone may be cut off or diluted by directing a suitable amount of the carbon dioxide across the surface of the body of liquid. This will -prevent a combustible fuel mixture from being formed. The forming of a combustible fuel mixture also may be prevented by cutting off the supply of oxygen or by diluting the supply of oxygen which Would normally reach the vapors rising from the surface of the fluid body. This cutting off or diluting the oxygen may be accomplished by discharging a suitable amount of carbon dioxide in a downward direction around the outside of the Walls of the tank, or other con- Hill; LAHliUUlOllLRO;

tainer, in which the inflammable fluid is normally confined. This type of discharge forces downwardly away from the top of the tank the air which would otherwise travel upwardly around the tank walls and reach the rising vapors to supply such vapors with oxygen. This external discharge also performs two additional functions. First, it cools the walls of the tank, or other container, to such an extent that sufficient heat may not be obtained therefrom to cause reflashing or rekindling of the combustible fuel mixture after discharge of the extinguishing medium has been stopped. Second, it extinguishes any fire resulting from inflammable fluid which is running down the side walls of the tank and extinguishes any fire which is consuming the walls of the tank if they are constructed of combustible material. The overflow of fluid may occur as a result of the fluid reaching its boiling temperature, or from some other cause.

Another characteristic peculiar to this type of fire is the likelihood of fluid being released from confinement through cracks, or other openings, formed in the side walls of the tank or casing as a result of the development of an excessive internal pressure. This liberated burning fluid, naturally, will spread over the area surrounding the involved tank or tanks and will spread the fire to adjoining properties if it is not extinguished. It is the usual practice, at least in the case of large outdoor electric transformers and circuit breakers, to cover a certain area around each installation with a layer of gravel, crushed stone, or the like, which will act to retard the spreading of the liberated fluids.

In further carrying out the method embodying this invention, carbon dioxide is discharged in a generally downward direction at a suitable number of points relative to the surrounding area. This downward discharge of the snow and vapor mixture effectively accomplishes extinguishment of the fire resulting from the liberated fluid. The carbon dioxide discharge referred to above as being delivered downwardly around and in contact with the side walls of the confining tank, to cut off the supply of oxygen for the main combustion zone, also assists in extinguishing the fire caused by the fluid which has been liberated from the tank and is spreading over the surrounding area.

To prevent this downwardly discharged extinguishing medium from spreading outwardly over too large an area and thereby losing its extinguishing value, as a result of lowered concentration, carbon dioxide is discharged in a generally inward direction from a suitable number of points around the margins of the area over which a high concentration of the extinguishing medium is desired. This inwardly discharged carbon dioxide effectively reduces dissipation of the downwardly discharged carbon dioxide and also helps to extinguish the fire coming from the released fluid.

As a result of all of this downwardly discharged carbon dioxide impinging against the surrounding ground, or other surface, and the turbulence created by the several discharges impinging against each other, a considerable deposit of snow is left on the involved area. For example, in the aforementioned extinguishment of several thousand gallons of oil in one minute, a discharge of approximately 6 tons of carbon dioxide produced a deposit of snow over an area which covered more than 1,000 square feet with the deposit in some portions of this area reaching a depth of from 4 to 5 inches. Such a deposit of snow made it literally impossible for any fire to survive over the thus treated area.

It is the primary object of this invention to provide methods and apparatus for extinguishing fires involving normally confined or well defined bodies of inflammable materials and particularly fluids.

A further important objectof the invention is to provide methods and apparatus for applying an extinguishing medium, such as carbon dioxide, to fires of the above mentioned types in such a manner as to effect complete extinguishment in an exceedingly short length of time and to lower the temperature of all associated bodies, objects, or masses to such a value that reflashing or rekindling of the combustible fuel mixture cannot occur.

Another object of the invention is the provision of methods and apparatus which embody the principle of eifecting extinguishment of fires by cutting off and/ or diluting the supply of fuel ingredients while traveling to the combustion zone with the result that a combustible fuel mixture will not be formed.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a diagrammatic plan View of a suitable form of fire extinguishing apparatus which.-

embodies this invention and which may be employed for carrying out methods of extinguishing fires involving large quantities of highly inflammable materials, such as confined fluids,

Figure 2 is a plan view of the apparatus disclosed diagrammatically in Fig. 1 and illustrates the arrangement of the apparatus for extinguishing fires involving the transformer oil contained in large outside power transformers and/or circuit breakers,

Figure 3 is a side elevational view of the apparatus disclosed in Fig. 2,

Figure 4 is a plan view of fire extinguishing apparatus embodying this invention which will operate to carry out methods of extinguishing fires involving large quantities of gasoline, oils, heating and cooking burner fuels, or the like, stored in a receiver of any suitable type,

Figure 5 is a side elevational view of the apparatus disclosed in Fig. 4,

Figure 6 is a view similar to Fig. 4 but illustrates a modified form of apparatus, and

Figure 7 is a side elevational view of the apparatus disclosed in Fig. 6.

In the drawings, wherein for the purpose of illustration are shown the preferred embodiments of this invention, and particularly referring to Figs. 1 to 3, inclusive, the referenc character A is employed for designating a transformer casing for a large capacity power transformer while the reference character B is employed for designating the casing of a circuit breaker or regulator for the transformer A. It is to be understood, however, that this specific illustration of a transformer casing and a circuit breaker or regulator casing is not given for the purpose of restricting or limiting the fire extinguishing method and apparatus to be described in connection therewith to this particular use as the casings A and B may both be transformer cases, circuit breaker cases, or tanks of any character which are employed sea Room for confining other highly inflammable fluids or materials. One of the principal purposes of the disclosure of Figs. 1 to 3, inclusive, is to illustrate the use of the methods and apparatus embodying this invention to provide fire protection for a plurality of relatively closely positioned storage containers which may be protected by a single installation.

The reference character C is employed in'Fig. 1 for designating a source of supply of liquid carbon dioxide. For fire protection of this nature, it is essential that a large quantity of liquid carbon dioxide be provided. The storage tank or container C, therefore, may have a capacity of from several hundred pounds up to several tons of liquid carbon dioxide. If desired, the supply of liquid carbon dioxide may b maintained in two or more large capacity storage tanks. The tank or tanks may be fixed and permanently connected to the carbon dioxide piping or distributing system, to be described at a later point, or the carbon dioxide to be employed may be confined in one or more transportable units which may be connected to the distributing system only in case of a fine.

The one or more storage containers may be insulated to retard the absorption of heat by the stored liquid carbon dioxide, if it is desired to maintain the extinguishing medium at a controlled temperature. If it is not desired to control the temperature of the extinguishing medium, the one or more storage containers may be left uninsulated. The insulated or uninsulated storage tank or tanks, if permanently attached to the distributing system, may be mounted above the surface or buried beneath the surface of the ground. If the extinguishing medium is to be maintained at a constant temperature, the burying of the container or containers has the advantage of subjecting the medium to a substantially constant, year-round temperature.

The reference character D designates a mechanical refrigerating unit which may be employed for maintaining the temperature, and the corresponding vapor pressure, of the stored liquid carbon dioxide at preselected values. This refrigerating unit is connected to a cooling coil, not shown, located within the container C by means of the pipe lines 11. The circulation of a suitable refrigerant through the cooling coil may be automatically controlled so as to maintain any desired temperature. It is preferred that the temperature, if controlled, be maintained at a relatively low value; for example, from +32 F. to -20 F. because of the advantages to be obtained from the use of such low temperature liquid carbon dioxide.

The advantages to be obtained from the use of low temperature, low pressure liquid carbon dioxide as a fire extinguishing medium are numerous. They are disclosed and claimed in the patents issued to Eric Geertz, No. 2,143,311, of January 10, 1939, and No. 2,202,434, of May 28, 1940.

The liquid carbon dioxide may be conducted to the numerous points of discharge from the one or more bulk storage containers C through one or more main discharge lines 6. The main discharge line or lines will be provided with a suitable control valve which is generally designated by the reference character I. This control Valve may be either directly manually operated or it may be operated by any suitable form of electrical or mechanical control mechanism which may be manual or automatic in its operation. Due to the bulk or large quantity storage means employed for the extinguishing medium, large diametered main pipe lines may be provided. Pipe lines having diameters from 3 inches to 6 inches have been employed for this purpose, and it has been determined that these large pipes may be used to effect discharge of the liquid carbon dioxide, even when maintained at a low, subatmospheric temperature, without producing a pressure drop which will cause solidification of the said liquid.

From the one or more main discharge lines 6, the liquid carbon dioxide is delivered to one or more manifold lines 8. It will be noted by closely inspecting Fig. 1 that the diameter, or size, of the manifold B is greater than the diameter, or size, of the main discharge line 6. Although the practice is not preferred, it has been definitely established that because of the large pipe sizes which are employed it is possible to discharge liquid carbon dioxide taken from bulk storage through succeeding pipe lines which are increased in diameter as much as 33%;% relative to preceding pipe lines without encountering any difiiculty as a result of the formation of snow at joints, valves, and points of discharge. The preferred practice, however, is to employ pipe lines of substantially uniform sizes.

From the manifold pipe line 8, the liquid carbon dioxide can be conveyed through any desired number of branch lines 9 and I0. Although only two of such branch lines are illustrated, it will be understood that a considerably greater number of such lines may be employed. Here again the total area of the flow path may be increased over that provided by the area of the flow path afforded by the manifold pipe line 8. The total area of the bores of the branch lines 9 and I0, however, preferably should not exceed the area of the bore of the manifold line 8. Each branch line 9 and Ill is provided with a manual or an automatic valve, all of which are designated by the reference character I3.

Coming now to the branch line 9, it will be seen that this line connects with two lines II and Na. To the end of line I I there are connected to sub-branch lines 14 and I5 and at the juncture of these two sub-branch lines there is connected a short length of pipe 16 which terminates in a discharge nozzle H. The subbranch line M has connected thereto additional, short lengths of pipe I8, l9, and 20. The outer ends of these relatively short pipes l8 to 20, respectively, have mounted thereon discharge nozzles 2|, 22, and 23.

The sub-branch line I5 has connected thereto short pipe sections 24 and 25. These pipe'se-c tions have mounted on their extremities the discharge nozzles 26 and 21, respectively.

Line Ila is illustrated in the several figures as having connected thereto the sub-branch lines 28 and 29. At the point of juncture between the line Ila and the sub-branch lines 28 and 29 there is connected a short pipe section 30 which has mounted on its extremity the discharge nozzle 3|. The sub-branch line 28 has short pipe sections 32 and 33 connected to one arm thereof while an additional length of pipe 34 is connected to a band or angle joint formed in this subbranch line. Discharge nozzles 35, 36, and 31 are respectively connected to the pipe sections 32, 33, and 34.

The sub-branch line 28 has connected thereto the pipe sections 38 and 39. The pipe section 38 has mounted on its extremity the discharge noz- 10b. illil; LXHNJUKSEHLHCS,

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zle 40 while the pipe section 39 has mounted on its extremity the discharge nozzle 4|.

Coming now to the branch line II], it will be seen that it is joined to two line I2 and l2a both of which extend to points adjacent the casing A where they each branch out into two sub-branch lines. Line l2 has two sub-branch lines 42 and 43. Sub-branch line 42 has connected thereto the pipe sections 44 and 45. The pipe section means of the type of discharge nozzle referred .to above.

As was pointed out in the introduction of this specification, one of the outstanding features of this invention is to discharge carbon dioxide relative to the top of a confining tank, casing, container, pool, or the like, so that the extinguishing medium will perform the several functions of cooling the fluid body, cooling the vapors rising 44 has a discharge nozzle 46 mounted on its exfrom the surface of said fluid body, and cooling tremity, while the pipe section 45 has a dis-charge the combustible fuel mixture 'below the point at nozzle 41 mount d n it xtremit which either ignition or combustion of the fuel A section of piping 48 is coupled into the sysmixture y Occurs type of carbon dioxide tem at the point of juncture between the line l2 discharge also is intended t0 either Completely d th t sub braneh lines 42 and 43, This cut off the flow of fluid vapors to the combustion pipe section 48 has a nozzle 49 mounted on its e 0! s0 materially dilute these vap that a ext t combustible fuel mixture cannot be produced.

The sub-branch line 43 has connected thereto In Figs- 1 130 inclusive, the IIOZZleS 35, the three pipe sections 50, 5|, and 52. The pipe and 4| for the casing B a d e nozzles section 50 has a discharge nozzle 53 mounted on 65, and ii for iilie Casing A e illustrated as its extremity while the pipe section 5i has a disbeing arranged t0 discharge the Cloud or stream charge nozzle 54 mounted on its extremity and of carbon dioxide n d po s dow w d y t pipe section 52 has a discharge nozzle 55 and inwardly relative to the tops of these casings mounted on t extremity or the surfaces of .the bodies of fluid confined The line l2a extends to a point substantially i Said casings. 0 attempt s been made to diametrically opposite the point at which the line illustrate y eXact r pecific angles for the disl2 splits off into its sub-branch lines. This line charge of these eve al nozzles. The angles of 12a also has connected thereto two sub-branch dlschorge ill depend entire y upon e various lines 55 and 5 The submmnch line 55 has factors involved. For example, variations in dipipe Sections 53 59, and so connected thereto ameter of the tops, or horizontal cross-sections, Discharge nozzles 6|, 62, and 63 are respectively of the involved casings Will be a dete minin connected to the pipe sections 58, 59, and 60. a The type of discharge nozzle and its par- At the juncture of the branch line l2a. and the P? of ge, also, must be taken into two sub branch lines 55 and 51, a pipe Section consideration. The angle of discharge of the 54 is connected and a discharge nozzle 55 is several nozzles foragiven hazard may be varied; mounted on its extremity. The sub-branch line the Vanous nozzles for a Single hazard y 51 has connected thereto pipe Sections 56, 61, and be arranged at difierent angles with respect to the 68. Nozzles 69, 10, and H are attached to the honzontal- Additionally, a greater or lesser respective extremities of these pipe sections 66, i of nozzles y e p yed Where the 5 and circumstances require such a modification. It

The above description refers to .the use of numerous discharge nozzles. Without intending to limit the disclosure to any particular form or type of discharge nozzle, it will be noted that the nozzle structure disclosed in the application filed in the name of Harry Ensminger, on December 22, 1938, Ser. No. 247,268, has been found to be extremely satisfactory because of its flexibility of operation. This type of discharge nozzle employs a diffuser member which maybe varied in shape, or may even be entirely dispensed with, to make possible a very wide variation with respect to the type of discharge. For example, the diffuser is employed for effecting spreading of the discharged cloud of carbon dioxide snow and vapors. By varying the shape of the diffuser, the discharged cloud may be spread or caused to flare outwardly to any desired degree or extent. By entirely dispensing with the diflfuser, the discharged stream or cloud is much more compact or condensed. Therefore, various modifications of this type of discharge nozzle may be employed to provide different types of discharge as they are needed to accomplish their intended function. For example, at certain points it will be desirable to have the discharged stream or cloud spread laterally to cover-a considerable area or space without the discharge being capable of carrying or traveling at a high velocity for a considerable distance. In other locations in the system, spreading of the discharged cloud or stream may not be essential but it may be highly desirable for the discharge to have a high velocity at a considerable distance from the nozzle. These various results may be obtained very readily by will be understood, however, that these nozzles are to be arranged in a suitable manner to accomplish the aforementioned function.

Another peculiarity or novel characteristic of the methods and apparatus embodying this invention deals with the discharge of carbon dioxide in a downward direction around the side walls of the tanks, casing, containers, or the like, for the purpose of cooling the side Walls of the same and for the additional purpose of cutting off the upward flow of air adjacent these side walls. This upward flow of air has been found to constitute the principal source of supply of oxygen for the main combustion zone which is located above the surface of the body of fluid which is involved. These downwardly directed streams or clouds of carbon dioxide are intended to perform the additional function of extinguishing fire which is either consuming the side walls of the tank or is consuming fluid which has overflowed the top of the tank or has escaped through a crack or other opening which has been formed in the side wall of the tank. Such side wall openings are frequently formed as a result of an excessive internal pressure developing within the tank.

In connection with the casing B, the discharge nozzles 22, 26, 35, and 40 are arranged to accomplish this desired result. With the container or casing A, the discharge nozzles 41, 54, B2, and 10 are provided for this purpose. It will be appreciated that a greater or a lesser number of nozzles of this character may be provided as the circumstances require.

A third important characteristic of this method and apparatus involves the downward discharge of carbon dioxide over a predetermined area surrounding the tanks or containers which are being protected. The area ot be covered by this type of discharge will vary considerably with different hazards. Therefore, no attempt has been made to lay downany particular standard or apply any particular limitations to this type of discharge. The discharge nozzles 23, 21, 46, 55, and BI are provided for this purpose. These nozzles will direct their clouds or streams of mixed carbon dioxide vapors and snow downwardly against the ground, or other surface, which surrounds the involved tanks, or other containers. This delivery of carbon dioxide over the involved, surrounding area, will function to extinguish any fire coming from fluids which have been permitted to escape from the involved containers and which are spreading over this surrounding area.

To maintain a desired high carbon dioxide concentration over this involved, surrounding area, it becomes desirable to prevent the downwardly discharged carbon dioxide from spreading out over too large an area. To accomplish this desired result, inwardly directed nozzles 2|,

31, 53, and 69 have been provided. These nozzles are arranged at the margins of the area to be protected. Any desired number of such nozzles may be employed. To avoid confusion, the present drawings only illustrate four of these marginal nozzles. Additional ones can be readily connected to the sub-branch lines I5, 29, 42, and 56 at their illustrated angles. Capped pipe sections are illustrated at these points and are all identified by the reference character I0.

As has been pointed out above, a considerable deposit of carbon dioxide snow is produced as a result of the downward discharge of carbon dioxide around the involved casings and at points spaced outwardly therefrom. These downwardly directed streams of carbon dioxide Will de posit their snow as a result of impinging against the ground, or other surface. The inwardly directed marginal streams of carbon dioxide, in impinging against the downwardly directed streams, also, will have the efiect of increasing the deposit of snow over the involved area. With the specific illustration set forth in Figs. 1 to 3, inclusive, a deposit of snow of from 4 inches to 5 inches in places was provided over an area which involved more than 1,000 square feet.

Coming now to the disclosure of Figs. 4 and 5, it was pointed out above that these figures are intended to illustrate the application of this method and apparatus to the protection of a single tank, or other container, as distinguished from a multiplicity of tanks, or containers. In this arrangement, the tank, or container, is designated by the reference character E. Branch lines H and I2 extend to this hazard from a suitable bulk storage source of supply such as that illustrated in Fig. 1.

The branch line H is connected to the two subbranch lines 13 and I4. The sub-branch line 13 has connected thereto the pipe sections I5, I6, and TI to the outer ends of which are connected the discharge nozzles I8, 19, and 80, respectively. The sub-branch line I4 has connected thereto pipe sections 8|, 82, and 83. Nozzles 84, 85, and 86 are attached to these respective pipe sections. At the juncture between the branch line II and the two sub-branch lines 13 and "I4, there is connected a pipe section 81 which has mounted on its extremity a. discharge nozzle 88.

The branch line 12 is divided into the two subbranch lines 89 and 90. The branch line 89 has connected thereto the pipe sections 9I 92, and 93. Discharge nozzles 94, 95, and 9B are attached to the ends of these pipe section SI, 92, and 93.

The sub-branch line 90 has attached thereto the pipe sections 91, 98, and 99 to which are attached the nozzles I00, IOI, and I02, respectively. At the juncture between the branch line I2 and the two sub-branch lines 89 and 90 there is connected a pipe section I03 to the extremity of which is attached a discharge nozzle I04.

Without attempting to repeat all of the description presented in connection with Figs. 1 to 3, inclusive, which apply to the mode of operation of this apparatus and the method carried out by means of the same, it will be stated that this apparatus functions in the same manner as the apparatus of Figs. 1 to 3, inclusive, and Will operate to carry out the previously described method. The discharge nozzles 88, 96, I02, and I04 are employed to apply the carbon dioxide in a proper manner to the area above the top of the tank or container E and the surface of the involved body of fluid. The nozzles I9, 85, 95, and IOI are employed for directing carbon dioxide downwardly around and adjacent to the side Walls of the tank or container E. The discharge nozzles and 83 are employed for directing carbon dioxide downwardly onto the area surrounding the involved tank or container E. The discharge nozzles 18, 84, 94, and I00 are arranged at the margins of the involved area and function to discharge carbon dioxide inwardly over this area to maintain the desired high concentration of carbon dioxide on and above the area.

Figs. 6 and 7 disclose a modified form of apparatus which may be employed for carrying out the method embodying this invention. This modified apparatus is illustrated in the manner in which it would be arranged to carry out the method of extinguishing a fire which involved a single hazard and is directly comparable with the apparatus and method disclosed in connection with Figs. 4 and 5. It is to be understood, however, that this modification of the apparatus obviously can be incorporated in the arrangement disclosed in Figs. 1 to 3, inclusive, in the same manner as it has been incorporated in the arrangement shown in Figs. 4 and 5.

The modification of Figs. 6 and 7 consists of employing sufficiently large carbon dioxide supply lines and carbon dioxide discharge nozzles to permit one set of such lines and nozzles to take the place of three of the four sets of supply lines and nozzles illustrated in the arrangements shown in Figs. 1 to 5, inclusive. These large supply lines and nozzles will operate to discharge a sufficiently large volume of carbon dioxide to accomplish the following:

a. Cooling, cutting 01f, and/or diluting the combustible fuel mixtures traveling to and being consumed at the principal combustion zone located above the confined bodies of materials to a temperature and a fuel mixture concentration below that at which burning will take place,

b. Cooling theexposed surface of the combustible material being consumed to a temperature below the ignition temperature of the combustible fuel mixture obtained from said material,

(2. Cooling the exposed sides of the container, tank, or the like in which the materials are confined,

d. Extinguishing any fire burning in the vicinity of the side walls of the container or tank 169. FIRE EXTINGUISEiEIi-J'S,

resulting from consumption of said side walls by the fire or consumption of the combustible materials flowing down the outer surfaces of said side walls,

e. Cutting off or diluting the upward flow of air around the side walls of the container, and

f. Creating a fire extinguishing concentration of carbon dioxide over a desired portion of the area surrounding the hazard or hazards.

With this modified apparatus, the smaller sized carbon dioxide lines and discharge nozzles, illustrated in Figs. 1 to 5, inclusive, are still employed for delivering carbon dioxide in a generally horizontal direction inwardly from the margins of the involved area surrounding the hazard or hazards to prevent or retard dissipation of the carbon dioxide. This modified apparatus arrangement will be described as follows:

In these figures the tank or container is designated by the reference character F. Branch lines I and I06 extend to this hazard from a suitable bulk storage source of supply of carbon dioxide, such as that illustrated in Fig. 1.

The branch line I05 is connected to the subbranch lines I01, I08, and I09.

I01 has connected to its extremity a discharge nozzle .0 which is of the same general siz and capacity as the discharge nozzles disclosed in Figs. 1 to 5, inclusive. The sub-branch line I91 is of a proper size to supply thi nozzle. branch lines I08 and I09 are sufliciently larger than the branch line I01 to properly supply the large discharge nozzles III and H2 which are connected to their respective extremities. The sub-branch line I09 has depending from a portion thereof the small extension [I3 which has a small nozzle I I4, of the size shown in Figs. 1 to 5, inclusive, connected to its extremity.

The branch line I06 has connected thereto the sub-branch lines H5, H5, and H1. branch line H5 has connected to its extremity a discharge nozzle US of the size disclosed in Figs. 1 to 5, inclusive. This sub-branch line I I5 is of a proper diameter to supply this size of discharge nozzle.

The sub-branch lines H6 and II! have large discharge nozzles H9 and I20 connected to their respective extremities. The sub-branch lines I I6 and II! are of proper size to adequately supply these large nozzles H9 and I20 with the required amount of carbon dioxide. The sub-branch line II I has depending therefrom an extension IZI 'which carries a discharge nozzle I22 at its lower end. This discharge nozzle is comparable with the nozzles IIO, I I4, and H8 or this modification.

It will be noted that the discharge nozzles I I I, H2, H9, and I20 are arranged at an angle with respect to the top of the tank or container F and the side walls of said container. Because of the large volume of carbon dioxide which may be.

discharged by means of these large nozzles, the cooling and extinguishing medium delivered by the latter will be adequate to carry out the steps of this method which involve the top of the container, the side walls of the container, and

the critical area surrounding the container.

The smaller sized nozzles H0, H4, H8, and I22 tionally, the disclosure of Figs. 6 and 7 is not in-- The branch line The The sub-" tended to act as a limitation regarding th number of nozzles employed. These various factors will be modified or varied depending upon the kind and size of hazard and the number of hazards involved.

It will be noted that the above descriptive matter and the figures 0f the drawings illustrate the invention by referring to tanks or containers which confine inflammabl materials and particularly highly inflammable fluids. These types of hazards have been selected because they are considered as presenting extremely troublesome problems. It is to be understood, however, that this invention is not to be construed as being limited to these types of hazards as th manner or method of applying carbon dioxide referred to above may be employed as effectively and as efficiently for extinguishing fires involving other types of hazards; for example, piles or masses of carbonation material It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, I claim:

1. A method of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising delivering to the combustion zone of the fire a sufficiently large volume of carbon dioxide to effect cooling of the fuel mixture of fluid vapors and oxygen to a temperature below that at which combustion can occur and to efifect dilution of the fuel mixture to a noncombustible value, and delivering carbon dioxide in a counter-current direction along paths through which air would normally travel to reach the vapors rising from the fluid body, thereby to reduce and dilute the supply of oxygen to the combustion zone of the fire.

2. A method of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising delivering to the combustion zone of the fire a sufliciently large volume of carbon dioxide to efiect cooling of the fuel mixture of fluid vapors and oxygen toa temperature below that at which combustion can occur and to effect dilution of the fuel mixture to a noncombustible value, delivering carbon dioxide across the surface of the fluid body so as to cut off the supply of vapors to the combustion zone of the fire, and delivering carbon dioxide in a counter-current direction along paths through which air would normally travel to reach the vapors rising from the body of fluid, thereby to reduce and dilute the supply of oxygen to the combustion zone of the fire.

3. A method of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising delivering to the area above the confining tank, and including the combustion zone where a fuel mixture of the fluid vapors and oxygen is being consumed by the fire, asufficiently large volume of carbon dioxide to effect extinguishment of the fire by cooling the fuel mixture to a temperature below that at which combustion can occur and by diluting the fuel mixture to a non-combustible value, and delivering carbon dioxide downwardly around and against the exposed side walls of the confining tank so as to effect cooling of said side walls, to effect extinguishment of fire burning on the surface of said walls and to prevent oxygen from reaching the combustion zone,

4. A method of extinguishing fires involving relatively large bodies of highly inflammable materials which are normally confined in tanks, or the like, comprising cooling and diluting the combustible fuel mixture being consumed at the principal combustion zone located above the confined materials to a temperature and a fuel mixture concentration below that at which burning will take place by delivering carbon dioxide to the combustion zone and the space between the surface of the confined body of materials and the combustion zone; and Cooling the exposed side walls of the confining tank, extinguishing any fire occurring in the vicinity of the side Walls of the tank, and cutting oil? the upward flow of air around the said side walls by discharging carbon dioxide downwardly around the outside of said side walls, said downward discharge being suficiently close to the side Walls of the confining tank to cause some of the carbon dioxide to be delivered thereagainst,

5. A method of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising cooling and diluting the combustible fluid vapor and oxygen fuel mixture, being consumed at the principal combustion zone located above the confined body of fluid, to a temperature and a fuel mixture concentration below that at which burning will take place by delivering carbon dioxide to the combustion zone and the space between the surface of the body of fluid and the combustion zone; cooling the exposed side walls of the confining tank, extinguishing any fire occurring from fluid running down the side walls of the tank, and cutting off the upward flow of air around the said side Walls by discharging carbon dioxide downwardly around the outside of said side walls, said downward discharge being sufficiently close to the side walls of the confining tank to cause some of the carbon dioxide to be delivered thereagainst; and extinguishing any fire coming from fluid which has escaped from the confining tank and is burning on the area surrounding the tank by discharging carbon dioxide downwardly over said surrounding area.

6. A method of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising cooling and diluting the combustible fluid vapor and oxygen fuel mixture, being consumed at the principal combustion zone located above the confined body of fluid, to a temperature and a fuel mixture concentration below that at which burning will take place by delivering carbon dioxide to the combustion zone and the space between the surface of the body of fluid and the combustion zone; cooling the exposed side walls of the confining tank, extinguishing any fire occurring from fluid running down the side walls of the tank, and cutting 01f the upward flow of air around the said side walls by discharging carbon dioxide downwardly at several difierent points around the outside of said side walls, said points of downward discharge being sufficiently close to the side walls of the confining tank to cause some of the carbon dioxide to be delivered thereagainst; extinguishing any fire coming from fluid which has escaped from the confining tank and is burning on the area surrounding the tank by discharging carbon dioxide downwardly over said surrounding area at several different points spaced outwardly from said tank walls; and maintaining a high concentration of carbon dioxide over the involved area surrounding the said tank walls by discharging carbon dioxide in a generally horizontal direction inwardly toward said walls from a plurality of points located around the margins of said involved area.

7. In the art of extinguishing fires involving relatively large bodies of highly inflammable materials which are normally confined in tanks, containers, or the like, having exposed side walls, the method step which comprises cooling the exposed side walls of the confining tank, extinguishing any fire burning in the vicinity of the side walls of said tank, and cutting off the upward flow of air around the said side walls by discharging carbon dioxide downwardly around the outside of saidside walls, said downward discharge being sufiiciently close to the side walls of the confining tank to cause some of the carbon dioxide to be delivered thereagainst.

8. In the art of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, having exposed side walls, the method step which comprises maintaining a high concentration of carbon dioxide over the area surrounding the side walls of the tank by discharging carbon dioxide in a generally horizontal direction inwardly toward said side walls from a plurality of points located around the margin of said involved area and adjacent the ground level.

9. In the art of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, having exposed side walls, the method which comprises extinguishing any fire coming from fluid which has escaped from the confining tank and is burning on the area surrounding the tank by discharging carbon dioxide downwardly over said surrounding area at several different points spaced outwardly of said tank walls, and maintaining a high concentration of carbon dioxide over the involved area surrounding the said tank walls by discharging carbon dioxide in a generally horizontal direction inwardly toward said walls from a plurality of points located around the margins of said involved area and adjacent the ground level.

10. In the art of extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, having exposed side walls, the method which comprises cooling the exposed side walls of the confining tank, extinguishing any fire coming from fluid running down the side walls, and cutting off the upward flow of air around the said Walls by discharging carbon dioxide downwardly at several different points around the outside of said walls, said points of downward discharge being sufficiently close to the side walls of the confining tank to cause some of the carbon dioxide to be delivered thereagainst; extinguishing any fire coming from fluid which has escaped from the confining tank and is burning on the area surrounding the tank by discharging carbon dioxide downwardly over said surrounding area at several different points spaced outwardly of said tank walls, and maintaining a high concentration of carbon dioxide over the involved area surrounding the said tank walls by discharging car- 169. RM EXTINGUISHERS,

Search 510cm bon dioxide in a generally horizontal direction inwardly toward said walls.

11. In the art of extinguishing fires involving masses of inflammable materials, the method step which comprises delivering carbon dioxide away from the main combustion zone of the fire and in a counter-current direction along paths through which air would normally travel to reach and deliver its oxygen to said main combustion zone, thereby to reduce the supply of oxygen to the fire.

12. Apparatus for extinguishing fires involving relatively large bodies of highly inflammable fluids which are normally confined in tanks, or the like, comprising a bulk storage source of supply of liquid carbon dioxide, a piping system including a main supply line leading from the said source of supply and a plurality of branch lines leading from said main line to a plurality of involved confining tanks, discharge devices connected to the outer ends of certain of said branch lines and arranged to deliver the carbon dioxide across the tops of the tanks, and discharge devices connected to the outer ends of others of said branch lines and arranged to deliver the carbon dioxide in a downward direction laterally outwardly of the side walls of said tanks but sufficiently close thereto to cause at least part of the discharged carbon dioxide to sweep downwardly over the side walls of the tanks.

13. Apparatus for extinguishing fires involving relatively large bodies of highly inflammable materials which are normally confined in suitable containers, comprising a bulk storage source of supply of liquid carbon dioxide, a piping system including a main supply line leading from the said source of supply and a plurality of branch lines leading from said main line to a plurality of locations relative to the involved container, discharge devices connected to the outer ends of certain of said branch lines and arranged to deliver the carbon dioxide across the top of the container, discharge devices connected to the outer ends of others of said branch lines and arranged to deliver the carbon dioxide in a downward direction laterally outwardly of the side walls of said container but sufiiciently close thereto to cause at least part of the discharged carbon dioxide to sweep downwardly over the said side walls, and discharge devices connected to the outer ends of still others of said branch lines and arranged to deliver the carbon dioxide in a downward direction over a desired amount of the area surrounding said container to provide a fire extinguishing concentration of carbon dioxide over said area.

14. Apparatus for extinguishing fires involving relatively large bodies of highly inflammable ma terials which are normally confined in suitable containers, comprising a bulk storage source of supply of liquid carbon dioxide, a piping system including a main supply line leading from the said source of supply and a plurality of branch lines leading from said main line to a plurality of locations relative to the involved containers, discharge devices connected to the outer ends of certain of said branch lines and arranged to deliver the carbon dioxide across the tops of the containers, discharge devices connected to the outer ends of others of said branch lines and arranged to deliver the carbon dioxide in a downward direction laterally outwardly of the side walls of said containers but sufiiciently close thereto to cause at least part of the discharged carbon dioxide to sweep downwardly over the side walls of the container, discharge devices con nected to the outer ends of still others of said branch lines and arranged to deliver the carbon dioxide in a downward direction over a desired amount of the area surrounding said containers to provide a fire extinguishing concentration of carbon dioxide over said area, and discharge devices connected to the outer ends of the remaining branch lines and arranged to discharge the carbon dioxide in a generally horizontal direction inwardly toward the sides of the containers from a plurality of points located around the margins of the involved area to maintain the required high concentration of carbon dioxide over the said area.

15. Apparatus for extinguishing fires involving relatively large bodies of inflammable materials which are normally confined in suitable containers, comprising a bulk storage source of supply of liquid carbon dioxide, a piping system leading from said source and including branch lines leading to a plurality of locations relative to the involved container, discharge devices connected to the outer ends of certain of said branch lines, said discharge devices and their associated branch lines possessing a total carbon dioxide delivery capacity and the devices possessing a delivery characteristic which will enable them to discharge carbon dioxide across the top of the involved container and downwardly around all sides of the container so as to extinguish the fire burning at the main combustion zone above the container and to extinguish fire burning in the vicinity of the side walls of the container while cooling all involved bodies and materials in these regions and creating a fire extinguishing atmosphere over a predetermined area surrounding the container, and discharge devices connected to the remaining branch lines and arranged to discharge the carbon dioxide in a generally horizontal direction inwardly toward the sides of the container from a plurality of points located around the margins of the involved area to maintain the required fire extinguishing atmosphere over the said area.

HARRY ENSMINGER. CHARLES A. GETZ. 

